Heavy metal health risk assessment in Cardisoma armatum Herklots, 1951 land crab tissues around Kribi mangrove areas, Cameroon

Abstract

Bioaccumulation of heavy metals in mangrove crabs has been reported and most of them are toxic to animals and potential human carcinogens. Given that the land crab Cardisoma armatum Herklots, 1951 is more consumed by surrounding populations, this study aimed to quantify the levels of metals in its tissues and to assess the human health risks. Soft tissues were isolated in adult crabs and frozen then; samples were dried, crushed and handled following the standard procedures. Human health risks were evaluated using some indices. Heavy metal levels in each tissue were shown in decreasing order: Fe > Zn > Al > Cu > Cd > Pb. Cadmium, lead and copper metals were in upper levels in the hepatopancreas (0.35, 0.19 and 7.88 mg/kg) whereas iron, aluminium and zinc were higher in muscles (129.30, 15.96 and 82.83 mg/kg). Most EDI values were apparently below the PTDI and CRLim values signifying that the consumption of C. armatum remains safe for consumers although, a limit in intake frequency might be required for children. For all metals, THQ and HI values were below the standard value 1 indicating no health risks in consumers due to the intake of single or several metals. Also, the carcinogenic risks for Cd and Pb metals are considered to be negligible because they are lower than 10⁻⁶. Overall, regarding the results, consumption of C. armatum seems harmless for human health in the study area.